The good,The bad and the ugly

[IRISH-RACER-14]

so i am a proud honda owner. owning the 300ex,the 400ex and the 450r.. all good reliable quads. never had any trouble. im thinking of moving to the kawi... is there any common problems on these bikes?id like to hear your feedback on them

[ish416]

I purchased my KFX450 new in October of 07 and have many hard hours on it and, from my experience, the KFX450 has been basically bulletproof.

I have had an issue with the stock exhaust header cracking twice but most titanium headers will do that eventually in my experience.

I have had fewer issues with my KFX450 than my 400EX I purchased new back in 99 during the first 3 years of ownership if that means anything.

[IRISH-RACER-14]

so if you were to buy a quad for reliabilitie and you had the option of the 400ex and the kfx450r,, you would choose the kfx just because its reliable?

[ish416]

I currently own both the 400EX and the KFX450. I purchased both brand new off the showroom floor.

If I were to purchase a sport quad just for reliability I would have to pick the 400EX. Mainly because there is less to go wrong with it. Also, they are low compression engines (9:1) and will last basically forever with proper maintenance. The issues that I had with the 400EX were blowing out the shocks constantly from racing MX and a few electrical issues due to a faulty wiring harness. I went through 3 rear shocks and 2 front shocks before Honda said that I was abusing the machine. My Honda has never left me stranded anywhere, but, neither has my Kawasaki.

The two are in completely different classes as far performance is concerned. My 400EX is now pretty well modded out. It has full after market suspension (stock a-arms and swing arm), a built 416 (12.5:1) with headwork and an XR400R cam. An FCR carb, KN filter, full exhaust and a few other things. My KFX450R is completely stock and totally kills the EX in every category except top speed where the KFX is about 3MPH faster both running stock gearing.

If you are interested in buying a KFX450 find one either at a dealership or maybe look for one on craigslist or ebay that is in your area and take it for a spin to see if you like it. Make sure you have the cash if your riding someones quad and not a dealerships as most people are of the "no cash, no ride" policy. Unless you have a friend that has one but if that were the case I'm sure you would already have your answer.

[IRISH-RACER-14]

how does the kfx compare to the other 450s? ill look out on craigslist for one. they go cheap

[scotturban]

Man I bought my kfx450 new and built it to race mx and its my favorite quad to ride when its running but truthfully motor has been extremely unreliable more problems with kawi then any of our other 450s honda, yamaha, and can-am, tons of electrical problems cant seem to still get them all figured out.

[Hetrick Racing]

Scott,
not to pick on ya but if it was done with the correct parts and correct mods,they are as reliable or more so than any other quad.

Now before I upset you which I have no intent to do,I will say we had our share of problems but we found the solutions and the quads became very very reliable.

Joel won something like 25(not sure if it was more but i know not less than) national motos this year and had 3 dnf's, one was my fault after he crashed at pell city the plastic mounts bent down and sliced the bat.wire and the second was a blown head gasket.The third was crazy he was passing for the lead at Danville,hangin so far off the left side of the quad his knee went up under the tank and broke the fuel line.
Thats it though out of 43 motos and 11 time qualifiers
Kawasaki KFX is in my opinion the best 450 on the planet

[Jigsaw]

Same as any other quad, take care of it and it will take care of you. Mines been great for the 2 years I've owned it. Glad I picked the KFX over the LTZ and Can AM

[scotturban]

I definatly agree with everything hetrick said. I bought my piston and cams from them also. Most of the problems I had with my kawi was when It was all stock motor, stock piston, stock crank, stock clutch all went pretty quick, then got new ones under warranty luckilly, then that lasted a some time until piston went out then we put a je in it, with all rest of motor stock then and it lasted a full year, on pump gas ran awesome. Then After that piston just went along with everything else in motor now everything is replaced aftermarket pretty much and no problems lately running good. I love my kawasaki though is why I have not got rid of it, a little pissed at it at times lol but I love the way it handles. For me the kfx feels so tiny and light compared to other 450s I have ridden, I am no pro-am rider, but for me I just love how easy the kfx is to jump and whip around and stuff its awesome. As for the power now its awesome. I can put it in 4th or 5th gear and take off and not worry about it bogging down.

[scotturban]

you said "The Good The Bad and The Ugly" Well I forgot the biggest part of all with the KFX there is no ugly, In My opinion most badass looking quad ever made. Especially with some mods haha

[ish416]

how does the kfx compare to the other 450s?

Here is my review of the quads that I have ridden. I have at least 10 hours of ride time on all of them. Except the Can-am which I have never rode.

YFZ450(carb'd) - Great all around quads, seem to be pretty solid as far as I am aware but, I am 6'3 and could not get comfortable on one even with a +4" steering stem. Seems to handle well and is very balanced all the time.

TRX450 - I do not have much good to say about them. I have seen so many break down and every one of them I have ridden has been a complete dog. Even my friends Bladwin Racing built 450R is a joke. Just pathetic quads in my opinion. The ergos and brakes are good tho. The handling to me seemed odd. All of the stock TRXs I have rode seem to have a really light front end that causes the front tires to push.

LTR450 - I really like them but they are to wide for the trails I frequently ride in. If you want an MX quad, this should be in your top 2. Need bigger tires for woods riding. Best handling stock quad I have rode. (Haven't ridden the YFZ450R or the Can-am MX)

Can-am - Never rode one.

Polaris 450 MXR - Surprisingly , I really like them. I have ridden a stock one on a track and through the trails and they handle great but need bigger tires if you are going to be using them in the woods much. I have ridden one with 20 inch tires, a homemade intake and exhaust and it was seriously an impressive quad given just the basic mods. They handle well and seem to have a sharpness to the handling. Suspension is also very good on the front but on the back, I could not get it dialed in.

KFX450 - The KFX450 is not the fastest or best handling, but does everything well. Also, reverse is handy in the woods and everywhere else when you need it. The throttle response is excellent and the thumb throttle has the smoothest travel of any quad I have ridden. It was a bit cramped in ergonomics stock but, I purchased 2" bar risers and it fits me perfectly. I purchased it without ever seeing or riding one (in Oct. 2007). It had everything in my checklist and the price was right. My checklist was:
1. EFI
2. Aluminum Frame
3. Major manufacturer (not Cannondale/ATK whatever they are now)
4. Decent Price

Engine wise, acceleration and top speed they are all fairly close and all do well with the basic mods.

The best thing you can do is go sit on or test drive them all and make your decision. After all, what works for me, may not work for you and vice-versa.

[IRISH-RACER-14]

kfx sounds good. i hope there are guys on the kfx forum to help me out when i eventually buy one. and scott.. i also agree that they are one of the nicest looking quads

[KFX450Rrider490]

i have to agree with everyone on here, theyve got some issues, but all quads do or will. if you do eventually buy one join the kfx450hq weve got those quads dialed

[Dirtjunkie85]

I have an 08 and the only 2 problems ive had was it was eating clutchs like no other until i switched to tusk and then i had to replace the programmer cause the wires got ripped out of them. i think its a matter of personal opinion because i know of other riders having problems with their brands... yamaha.. can-am... honda... suzuki..

[scotturban]

Yeah I went though a couple stock clutches also, Have 450r/kfx450 components together now and its holding up

[MtnEX]

Originally posted by Hetrick Racing
Scott,
not to pick on ya but if it was done with the correct parts and correct mods,they are as reliable or more so than any other quad.

Now before I upset you which I have no intent to do,I will say we had our share of problems but we found the solutions and the quads became very very reliable.

Joel won something like 25(not sure if it was more but i know not less than) national motos this year and had 3 dnf's, one was my fault after he crashed at pell city the plastic mounts bent down and sliced the bat.wire and the second was a blown head gasket.The third was crazy he was passing for the lead at Danville,hangin so far off the left side of the quad his knee went up under the tank and broke the fuel line.
Thats it though out of 43 motos and 11 time qualifiers
Kawasaki KFX is in my opinion the best 450 on the planet

I agree with the above...

Mechanically they are really bulletproof...

I'd say the motor, trans and frame are by far the most trustworthy of all the 450's.

However, they do indeed have their electronic "gremlins" for sure.

I resolved my gremlins with an aftermarket ECU... and up until now I have been able to find any confusing thing with a multimeter because there is a test for everything.

However, now I have this random hard starting when cold, random miss at idle sometimes... and the really easy stalling in the woods with no warning too... and I have this "burble" going on when holding a steady throttle with low or no engine load.

Do you guys at Hetrick have any ideas on that?

TPS is good now, battery voltage good, fuel is good....

We have no good way of home testing the two air sensors, but it does the same thing if they are disconnected.

Only thing else I can find suspect is the crank sensor checks out low on resistance... 18... And the rectifier results are a little confusing but the battery is holding up.

[Hetrick Racing]

The random stall could be as simple as your throttle plate has a bit of build up on it(have seen that before same condition)or the plate could be off on adjustment.Your choke(idle) should be in the middle or somewhere close,if it is not adjust your throttle stop (and your tps ) so you can set the idle in or around the middle.
This also could be your hard start cold.

The burble we i have to ask is the head ported ? or the throttle body bored?
If not have to say you need to map it on a dyno starting @10% throttle all the way up should solve that.
If it is ported you may have to deal with it.
When we first started with these we had a few that would "search" at certain rpms.

[scotturban]

by the way there was a point when my quad would just crank and crank with the electric start when it was hot, I got tired of trying to figure out the electronic crap, put the kick start kit on it, will start no problem with that? but still stuck with the battery till somebody finds out how to get rid of it

[MtnEX]

Originally posted by Hetrick Racing
The random stall could be as simple as your throttle plate has a bit of build up on it(have seen that before same condition)or the plate could be off on adjustment.Your choke(idle) should be in the middle or somewhere close,if it is not adjust your throttle stop (and your tps ) so you can set the idle in or around the middle.
This also could be your hard start cold.

The burble we i have to ask is the head ported ? or the throttle body bored?
If not have to say you need to map it on a dyno starting @10% throttle all the way up should solve that.
If it is ported you may have to deal with it.
When we first started with these we had a few that would "search" at certain rpms.

Stock motor and throttle body... until I "need" to do internal work.

That will give me something else new to look for... thanks... I'll pull the throttle body and have a look.

[MtnEX]

Originally posted by Hetrick Racing
The random stall could be as simple as your throttle plate has a bit of build up on it(have seen that before same condition)or the plate could be off on adjustment.Your choke(idle) should be in the middle or somewhere close,if it is not adjust your throttle stop (and your tps ) so you can set the idle in or around the middle.
This also could be your hard start cold.

The burble we i have to ask is the head ported ? or the throttle body bored?
If not have to say you need to map it on a dyno starting @10% throttle all the way up should solve that.
If it is ported you may have to deal with it.
When we first started with these we had a few that would "search" at certain rpms.

You know what?....

I finished up on things I was checking over and decided to try firing it up before actually taking the throttle body on off...

It ran fine... but then this afternoon it didn't want to cold start. So I tried adding a little fuel to the bottom to get it starting better.

It was then that it hit me....

I have not touched that d@mn knob not once since I set it 6 months ago... haven't clicked it... haven't pulled it out.

I touched it though at the first stubborn cold start... pulled it out.

The point being that was the thing I did not think of that has been different lately. So I went back to it while it was running... and if I fiddle with it, I can get my intermittent problem flaring up.

I can pull it out and push it back in... and it will start it's crap... puh!... dead miss.

I can get it settled back out and go like I am going to click it one click and it will start soon as I reach the point before it clicks.

I can turn it slower a few clicks from 1800 and it sounds like a rattletrap...


Throttle body needs to come off I guess.


I would just like to have some understanding of how in the world that idle knob can have anything to do with anything?

In other words I have no clue how it works. Figured this out by monitoring TPS output and messing with it. It don't change the output... so it works different than I thought.

[Dirtjunkie85]

agree with Hetrick Racing. LOVE the kawi.

[MtnEX]

Originally posted by Hetrick Racing
The random stall could be as simple as your throttle plate has a bit of build up on it(have seen that before same condition)or the plate could be off on adjustment.Your choke(idle) should be in the middle or somewhere close,if it is not adjust your throttle stop (and your tps ) so you can set the idle in or around the middle.
This also could be your hard start cold.

The burble we i have to ask is the head ported ? or the throttle body bored?
If not have to say you need to map it on a dyno starting @10% throttle all the way up should solve that.
If it is ported you may have to deal with it.
When we first started with these we had a few that would "search" at certain rpms.

I took the throttle body off and apart.

I couldn't see any issues.

How do you know rather or not the throttle stop is set correctly???


Here is a video for you... revs crisp and clean as a whistle... steady throttle and it burbles like crazy!

http://www.youtube.com/watch?v=L4DphGSrGIY

[JBacon]

What about the motor since it is a racing bike are the parts like made to last long or is it like a rebuild every year thing? I only plan on doing woods and trail riding so mine wouldn't be for MX hardcore racing or anything.

[strubby]

It will be reliable with proper maintainance. You will have to do more fequent oil changes and such than your 400ex, but it's a much more powerful and versatile machine. Coming from a TRX450R, the bike felt nearly as powerful stock as my Honda with a full exhaust, Pro Design intake, HCII and jetted. For the woods, I think it's one of the best options.

[MtnEX]

Originally posted by JBacon
What about the motor since it is a racing bike are the parts like made to last long or is it like a rebuild every year thing? I only plan on doing woods and trail riding so mine wouldn't be for MX hardcore racing or anything.

You will catch me complaining about things on the KFX.

The mechanical engine internals are not one of those things though. So far, to me these things seem pretty darn bullet proof with regular oil changes, high quality oil and just good sensible maintenance.

I bought mine new left over in '09 and it does not have as much time on it as I would have liked to put on it... but still in has quite a bit of hours... and literally... as far as I can tell it still seems brand new internally. No wear I can detect on anything, and it still has exactly the same compression it had right after break-in.

Furthermore, it does not seem that anyone is complaining of any sort of engine failure or frequent rebuilding... and I talk to a lot of KFX guys on a daily basis.